Wave energy converter

ABSTRACT

A wave energy generator includes a float for floating on the surface of a body of water. An electrical energy generator that is capable of generating usable electrical energy from the kinetic energy of waves is mounted to or otherwise engaged with the float. The electrical energy generator includes a housing, a coil of electrically conductive material, a reciprocally movable electromagnetically active mass, and springs for connecting the mass to the housing. The electrical energy generator may optionally include spring adjustment means engaged with the housing, means for constraining non-linear motion of the electromagnetically active mass, and/or means of mitigating motion retardation of the electromagnetically active mass within the housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date under 35 U.S.C.§119(e) of U.S. Provisional Application For Patent No. 61/034,715 filedon Mar. 7, 2008, which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The disclosure relates to a wave energy generator that includes abuoyant element, such as a bouy or float, which is engaged with anenergy generator that is capable of generating electrical energy fromcaptured kinetic energy of waves. The device permits the capture ofkinetic energy imparted to the buoyant element from movement, such aswaves on the surface of bodies of water, and the conversion of thecaptured kinetic energy into electrical energy. The device may be usedto provide electrical power to a wide variety of electronic devices.

BACKGROUND

Mechanical energy comprises a number of forms of energy including, butnot limited to kinetic energy. Kinetic energy is the energy of a mass inmotion. Kinetic energy is manifested in the motion of fluids which havemass and in masses moved by moving fluids. Fluids comprise liquids andgases, for example, air and water are both examples of fluids. Both airand water are put into motion by common atmospheric and hydrosphericphenomena. Such motion appears, among other things, as wind, waves,tides, seiches, and currents.

It is sometimes desirable to convert mechanical energy to electricalenergy. An example is the conversion of kinetic energy into electricalenergy as the kinetic energy of a mass moves a magnetic field relativeto a conductive coil thereby converting the kinetic energy of the massto electrical energy by action of electromagnetic induction.

The world is becoming more dependent on energy sources. As a result ofthis increasing dependence, traditional energy sources are becomingexhausted. There have been efforts made to develop renewable andsustainable alternative sources of energy. Some of these alternativeenergy sources include solar power, wind power and hydropower.

Accordingly, it is desirable to provide an improved device to convertthe kinetic energy manifested in waves into electrical energy in orderto maximize the amount of electrical energy that may be generated foruse.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one illustrative embodiment of theelectrical energy generator.

FIG. 2 is a perspective view of another illustrative embodiment of theelectrical energy generator.

FIG. 3 is a perspective view of an illustrative embodiment of the waveenergy

generator.

FIG. 4A is n perspective view of another illustrative embodiment of thewave energy generator.

FIG. 4B is a perspective view of another illustrative embodiment of thewave energy generator.

FIG. 5 is a perspective view of another illustrative embodiment of thewave energy generator in electrical communication with an offshoreelectrical distribution center.

DETAILED DESCRIPTION

Provided is a wave energy generator comprising a float and an electricalenergy generator engaged with the float comprising a housing having alongitudinal axis, an interior cavity, an interior cavity surface, andan exterior surface, an electrically conductive material engaged aboutat least a portion of said exterior surface of said housing andextending along at least a portion of said longitudinal axis, anelectromagnetically active mass positioned within said housingreciprocally movable along at least a portion of said longitudinal axisa first spring having first and second ends, wherein one end is engagedwith said housing and one end is engaged with said electromagneticallyactive mass, and a second spring having First and second ends, whereinone end is engaged with said housing and one end is engaged with saidelectromagnetically active mass.

According to certain illustrative embodiments, the electromagneticallyactive mass is constrained within the housing of the energy generator tosubstantially prevent non-reciprocating motion of saidelectromagnetically active mass within said housing.

According to other embodiments, the wave energy generator comprises afloat and an electrical energy generator engaged with the floatcomprising a housing having a longitudinal axis, electrically conductivematerial engaged about at least of portion of the exterior surface ofsaid housing and extending along at least a portion of said longitudinalaxis, an electromagnetically active mass positioned within said housing,said mass reciprocally movable along at least a portion of saidlongitudinal axis, a first spring having first and second ends, whereinone end is engaged with said housing and one end in engaged with saidelectromagnetically active mass, a second spring having first and secondends, wherein one end is engaged with said housing and one end isengaged with said electromagnetically active mass, and a means tomitigate motion retardation of said electromagnetically active masswithin the housing.

According to further embodiments, the wave energy generator comprises afloat and an electrical energy generator engaged with the floatcomprising a housing having a longitudinal axis, an interior cavity, aninterior cavity surface, and an exterior surface, an electricallyconductive material engaged about at least a portion of said exteriorsurface of said housing and extending along at least a portion of saidlongitudinal axis, an electromagnetically active mass positioned withinsaid housing reciprocally movable along at least a portion of saidlongitudinal axis, a first spring having first and second ends, whereinone of said ends is engaged with said electromagnetically active mass,and a second spring having first and second ends, wherein one of saidends is engaged with said electromagnetically active mass, and at leastone spring deflection adjustor engaged with said housing and at leastone of said springs.

The electrical energy generator generally comprises a housing, aninduction coil, an electromagnetically active mass movable in areciprocating manner relative to the housing, and at least one springengaging the electromagnetically active mass to the housing.

According to certain illustrative embodiments, the electrical energygenerator generally comprises a housing, an induction coil, anelectromagnetically active mass movable in a reciprocating mannerrelative to the housing, a first spring engaged with the mass and thehousing, and a second spring engaged with the mass and the housing.

According to further illustrative embodiments, the electrical energygenerator comprises a housing, an induction coil, an electromagneticallyactive mass movable in a reciprocating manner relative to the housing, afirst spring engaged with the mass and the housing, a second springengaged with the mass and the housing, wherein the electromagneticallyactive mass is constrained within the housing to minimize or otherwisesubstantially prevent non-reciprocating movement of the mass.

According to other illustrative embodiments, the electrical energygenerator comprises a housing, an induction coil, an electromagneticallyactive mass movable in a reciprocating manner relative to the housing, afirst spring engaged with the mass and the housing, and a second springengaged with the mass and the housing, and means of mitigating motionretardation of the electromagnetically active mass within the housing.

According to additional illustrative embodiments, the electrical energygenerator comprises a housing, an induction coil, an electromagneticallyactive mass movable in a reciprocating manner relative to the housing, afirst spring engaged with the mass and the housing, and a second springengaged with the mass and the housing, and at least one springdeflection adjuster.

It should be noted that the electrical energy generator may include acombination of two or more of means for constraining thenon-reciprocating movement of the electromagnetically active mass withinthe housing, means for mitigating motion retardation of theelectromagnetically active mass within the housing, and at least onespring deflection adjustor.

The device harvests mechanical energy and converts the harvestedmechanical energy into electrical energy. By harvesting mechanicalenergy from the reciprocating mass and convening it into electricalenergy, the device acts as a linear electrical generator. The generatedelectrical energy may be used to power a wide variety of electronicdevices including, without limitation, locators, signaling equipment,entertainment equipment, energy storage equipment, radio receivers,radio transmitters, wireless telephones, cameras, global positioningsystem (GPS) equipment, and like electronic devices.

According to other illustrative embodiments, the wave energy generatormay harvest mechanical energy from the motion of waves, convert theharvested mechanical energy into usable electrical energy and transferthe energy to an electrical distribution system, such as an electricalgrid or electrical station. It should be noted that the wave energygenerator can supply usable electrical energy to an electricaldistribution system, such as an electrical grid or electrical station,that is located cither onshore or offshore.

The housing of the device may comprise any suitable structure, capsule,container, or vessel that is capable of engaging the other components ofthe electrical energy generator. The housing general includes alongitudinal axis, an exterior surface, an interior cavity, and aninterior surface. Without limitation, according to certain embodiments,the housing comprises an elongated cylinder or tube having an interiorcavity or volume.

The housing may be constructed of any material that can support theengagement of device components and that does not interfere with theharvest of mechanical energy or conversion of the mechanical energy intoelectrical energy. Without limitation, suitable material that may beused to construct the housing of the device comprises metal, metalalloys, plastic, glass, composite materials, or combinations thereof.

The linear electric energy generator may be scaled in a water-tighthousing. The sealing of the generator within the housing protects itfrom the environmental elements. Scaling the generator also permits avacuum to be pulled inside the sealed housing, or permits thecontainment of a gas within the housing to mitigate motion retardationof the electromagnetically active mass. According to other embodiments,the housing may not be scaled, however, the float or bouy in which thelinear electric energy generator is located must be scaled.

According to other embodiments, the housing comprises a closed structuresuch that the interior of the housing is substantially isolated from theenvironment surrounding the housing. According to embodiments includinga closed housing, the housing atmosphere need not be substantiallyidentical to the surrounding external environmental atmosphere. Forexample, without limitation, the housing atmosphere may comprise air,nitrogen, a Nobel gas, mineral oil, vegetable oil, water, saline,substantial vacuum, a ferrofluid, or combinations thereof.

The device includes an electrically conductive material that is engagedabout at least a portion of the exterior surface of said housing.Without limitation, the electrically conductive material may be providedin the form of an induction coil. The induction coil may include anarmature, inductor, wire coil, or any other looped electricallyconductive material. A change in a local magnetic field produces acurrent within and a potential across an induction coil. Because theinduction coil is engaged about the housing and extends along a portionof the axis of the housing, a change in a magnetic field proximal tothat portion of the housing engaged with the induction coil produces acurrent within and a potential across the induction coil. An additionalhousing may be positioned about the induction coil in order to provide asealed, water-tight electrical energy generator.

The device includes at least one spring engaging the electromagneticallyactive mass to the housing. The springs generally have opposite firstand second ends, and are engaged at one end with the housing and at theother end with the electromagnetically active mass. A spring is anycomponent which produces a restorative force in response to itsdisplacement. Certain springs produce restorative forces directlyproportional to their displacement. Springs which produce restorativeforces directly proportional to their displacement are springs whichobey Hooke's Law. A spring accumulates mechanical energy in the form ofpotential energy as work is done upon it and releases it as theabove-referenced restorative force. The relationship between therestorative force and the displacement is the spring coefficient. Insprings which obey Hooke's Law, the spring coefficient is substantiallyconstant.

According to certain illustrative embodiments, the electrical energygenerator includes first and second springs that obey Hooke's Law. Thesefirst and second springs arc attached to opposite ends of the devicehousing and to opposite ends of the electromagnetically active mass thatis located within the device housing. Because these springssubstantially obey Hooke's Law, the springs arc considered to beharmonic oscillators and can provide a natural frequency. In certaincircumstances, however, it may be advantageous to utilize springs thatpossess stiffening spring characteristics such that at the end oftravel, there would be no need to incorporate any rebound means with thedevice.

In certain embodiments, the springs included in the device comprise coilsprings. A coil spring is a type of torsion spring. A coil springcomprises an elastic material formed into a helix, or spiral, or spiralhelix having two opposite ends. The coil springs may comprise eithercompression springs or extension springs.

A spring pre-load is a load that exists in the spring prior todeflection of the spring from some initial state. As used herein,pre-load of a spring refers to the load in the spring in the unexciteddevice in which the electromagnetically active mass is at rest. Thedevice may also include a suitable means for adjusting the deflection orspring pre-load on the coil springs. A means of adjusting springpre-load comprises any component which introduces or removes a load,tension or compression of an installed spring, usually in the unexciteddevice. Introduction or removal of a load of an installed spring may bedone by adjusting the deflection of the spring. In certain embodimentsthe means of adjusting spring pre-load and deflection comprises amovable member with which the spring to have its pre-load and deflectionadjusted is engaged. In such embodiments, the region of engagementbetween the spring and the member is movable with respect to thehousing. In certain embodiments, the moveable member comprises athreaded member. Threaded members may comprise screws, bolts, andthreaded bushings. In certain embodiments, the threaded member isengaged with a counterpart threaded receiver that is substantially fixedto or integral to the housing. One illustrative method of moving thepoint of engagement between the spring and the threaded member withrespect to the housing is by advancement or retraction of the threadedmember by rotating the threaded member with respect to the threadedreceiver. As the threaded member is rotated, the threaded member and theregion of engagement between the spring and the member moves helicallywith respect to the threaded receiver, and thereby moves helically withrespect to the housing. The amount of movement will be equal to theproduct of the thread pitch and the number of rotations made. The amountof change in the load will be equal to the product of the amount ofmovement and the spring coefficient.

In certain embodiments, the springs comprise a first spring having afirst end engaged with the housing and a second end engaged with saidelectromagnetically active mass, and a second spring having a first endengaged with the housing and a second end engaged with saidelectromagnetically active mass. In certain embodiments, the springscomprise a first spring having a first end engaged with a first threadedmember and a second end engaged with said electromagnetically activemass, and a second spring having a first end engaged with a secondthreaded member and a second end engaged with said electromagneticallyactive mass.

As used in this disclosure, “electromagnetically active” refers to amass that is capable of affecting a magnetic field. Electromagneticallyactive components include, but arc not limited to. permanent magnets,electromagnets, inductors, and materials having magnetic permeability.The electrical energy generator may comprise one or moreelectromagnetically active components to affect a desired magneticfield.

An electromagnetically active mass may be any electromagnetically activecomponent which also has mass. An electromagnetically active mass iscapable of producing a magnetic field or bending the flux lines of amagnetic field. Electromagnetically active masses capable of producing amagnetic field comprise permanent magnets, electromagnets and the like.Electromagnetically active masses capable of bending the flux lines of amagnetic field may also comprise materials having magnetic permeability.In certain embodiments, the materials having magnetic permeability arematerials which have a high permeability. Without limitation, materialswhich have a high permeability comprise iron, nickel, chromium, and likematerials. In certain embodiments, an electromagnetically active massmay comprise metal, metal alloys, ceramics, and mixtures thereof.

The electromagnetically active mass is positioned within the interiorcavity of the housing and is engaged with each of two coil springs, witheach of the coil springs being further engaged with the housing. Themanner of engagement of the springs and mass allows theelectromagnetically active mass to move in a reciprocating manner withrespect to the housing. The electromagnetically active mass defines avolume which is swept out by the electromagnetically active mass as itmoves. The volume which is swept out by the electromagnetically activemass as ii moves is at least a portion of the volume of the interiorcavity of the housing.

The shape of the electromagnetically active mass can vary greatly, andthere is no particular shape to which the electromagnetically activemass must be limited. In certain embodiments, the electromagneticallyactive mass comprises an axisymmetric shape. In certain embodiments, theelectromagnetically active mass comprises substantially cylindricalshape.

In certain embodiments, the electromagnetically active mass comprises atleast one through-hole. In certain embodiments the electromagneticallyactive mass is a substantially cylindrical axisymmetric mass comprisinga through-hole.

A guidance means comprises any component that comprises a portion of thehousing, or that is engaged to or integral with, the housing and has aguidance surface for the electromagnetically active mass over at least aportion of the path described by the mass as it moves. In certainembodiments, the material of the guidance means comprises metal,plastic, glass, composite materials, or combinations thereof. In certainembodiments the guidance surface of the guidance means comprises asurface coating. The surface coating may comprise metal, plastic, glass,composite materials, or combinations thereof. In certain embodiments theguidance means, or the guidance surface of the guidance means, maycomprise PTFE, PEEK, or oil-impregnated bronze. The guidance surface ofthe guidance means may substantially coincide with at least a portion ofthe surface of the volume swept out by the electromagnetically activemass as it moves. According to certain embodiments, the guidance meansguides the mass by providing restorative forces to the mass indirections substantially normal to the surface of the means in responseto contact between the mass and the means. These restorative forces arereferred to as “normal forces”. By providing such restorative forces,the guidance means impedes motion of the mass in directions normal tothe means. In certain embodiments, the mass may be engaged with theguidance means during all portions of the motion of the mass. In certainembodiments, the mass is constrained by the guidance means to minimizesubstantially all motion of the mass other than linear reciprocation,such that motion of the mass is limited to substantially linearreciprocation. There will exist a coefficient of friction determined bythe material of the guidance surface and the material of theelectromagnetically active mass which contacts the material of theguidance surface. The product of the coefficient of friction and thenormal forces defines the magnitude of friction forces between the massand the means which retard the motion of the mass. In certainembodiments, the coefficient of friction is selected to be very low inorder to minimize the magnitude of friction forces.

In certain embodiments, the guidance surface of the guidance meanscomprises the interior surface of the housing. In certain embodiments,in which the electromagnetically active mass comprises at least onethrough-hole, the guidance means comprises a shaft or rod passingthrough a through-hole and along which said electromagnetically activemass moves as it reciprocates.

The electrical energy generator may further comprises a means ofmitigating motion retardation of the electromagnetically active mass bythe housing atmosphere. The housing atmosphere comprises a fluid,wherein such fluid may be a gas or a liquid. Fluids arc known to retardthe motion of materials through them. In certain circumstances, thehousing atmosphere will retard the motion of the electromagneticallyactive mass through the housing atmosphere.

One type of retardation of the motion of the electromagnetically activemass is by viscous effects. Viscous effects which retard motion appearwhenever a body moves through a fluid having a positive viscosity. Onemeans of mitigating motion retardation by viscous effects is byrarification or evacuation of the housing atmosphere. In certainembodiments, the housing atmosphere comprises a gas at sub-atmosphericpressure, such that the housing atmosphere is reduced, rarified, orevacuated to the point that it comprises a substantial vacuum.

Retardation of the motion of the electromagnetically active mass mayoccur by pressure differentials. Pressure differentials may be createdby motion of an object within, and in close clearance to, a closedhousing. In certain embodiments, the electromagnetically active mass maybe engaged in very close tolerance to a closed housing. One means ofmitigating motion retardation by pressure differentials is by theinclusion of apertures, flow-paths, flutes, or ducts to permit flow fromthe region into which the mass is moving and to the region from whichthe mass is moving. In certain embodiments, the interior surface of thehousing may comprise longitudinal flutes to permit flow of the fluidcomprising the housing atmosphere from one region of the interior cavityto another region of the interior cavity. In certain embodiments theelectromagnetically active mass may comprise one or more through-holesor flutes which permit flow of the fluid comprising the housingatmosphere around, across, or through the mass.

According to certain embodiments, the electrical energy generator mayfurther comprise an electromagnetically active shroud that is engagedwith the housing and at least partially covering the induction coil. Incertain embodiments, the electrical energy generator comprises anelectromagnetically active shroud that is engaged with the housing whichat least partially covers said housing. In certain embodiments, theelectrical energy generator comprises an electromagnetically activeshroud that is engaged with the housing which partially covers saidhousing. In certain embodiments the electrical energy generator maycomprise an electromagnetically active shroud that is engaged with thehousing which fully covers said housing. In certain embodiments theelectromagnetically active shroud may comprise a permanent magnet. Incertain embodiments, the electromagnetically active shroud comprises anunmagnetized material having magnetic permeability. In embodiments inwhich the electromagnetically active mass comprises an unmagnetizedmaterial having magnetic permeability, the device will further comprisean electromagnetically active shroud which comprises a permanent magnet.In certain embodiments in which the electromagnetically active masscomprises a permanent magnet, the device comprises anelectromagnetically active shroud comprising an unmagnetized materialhaving magnetic permeability.

The electrical energy generator comprises an electromagnetically activemass which reciprocates within the housing. Exciting forces acting onthe housing excite the mass causing it to move within the housing in areciprocating manner which is substantially harmonic. Further, theelectrical energy generator comprises components which remove mechanicalenergy from the mass when it is in motion, thereby electromagneticallydamping it. Because of these properties, certain embodiments of theelectrical energy generator may be described as a substantially harmonicdamped oscillator. It should be noted that the damping of the energyfrom the mass may comprise critically damping, greater than criticallydamping or less than critically damping. According to certainillustrative embodiments, the damping of the energy from the masscomprises less than critical damping. According to yet furtherembodiments, the damping of the energy of the mass may be variable.

When a driving force is acting on the electrical energy generator,according to certain embodiments, the device behaves as a substantiallyharmonic driven, damped oscillator. Harmonic oscillators have afundamental or natural frequency which is a function of oscillating massand spring coefficient. Because the mass of the electromagneticallyactive mass is determinable and because the spring coefficient of thespring is determinable, the natural frequency of the device is alsodeterminable. The selection of the mass or spring coefficient or both toadjust the natural frequency of the device is referred to herein as“tuning”. That is, the natural frequency of the device may be tuned byselection of the mass or the spring coefficient or both.

Because the mass, by definition, has inertia, an exciting force directedto the device along a direction which is not perpendicular to the axisof reciprocation, causes the housing to be displaced to a greater extentthan the mass is caused to be displaced. This difference in displacementcauses some of the exciting kinetic energy imparted by the action of theexciting force acting over said displacement to be absorbed by theelectromagnetically active mass, the springs and the induction coil.

Because the electrical energy generator includes an electromagneticallyactive mass, a spring, and an induction coil, when set into motion, thedevice can behave as a damped vibrating system and will vibrate until itdissipates the exciting energy. The natural frequency or frequencies ofthe harvester can be predetermined. Without limitation, in certainembodiments, the electrical energy generator behaves as a substantiallyharmonic oscillator having one natural frequency. The level of dampingin the device can be predetermined.

The certain illustrative embodiments of the device will be described infurther detail with respect to the Figures. It should be noted that theelectrical energy generator should not be limited to the illustrativeembodiments depicted by the Figures.

As shown in FIG. 1, the device (110) comprises a housing (120) whichcomprises an elongated circular cross-section tube having first andsecond ends. The housing (120) comprises an internal cavity (122)defined by the tube, an interior surface (124) and an atmosphere (126).The device further comprises a first spring (130) having a first end anda second end. Spring (130) comprises an extension coil spring having thefirst end attached to the first end portion of the housing (120). Thedevice further comprises a second spring (132) having a first end and asecond end. Spring (132) comprises an extension coil spring having thefirst end attached to the first end portion of the housing (120). Thedevice (110) further comprises an electromagnetically active mass (140)engaged with each of springs 130 and 132. The electromagnetically activemass (140) is moveable within said housing (120). Theelectromagnetically active mass (140) moves in a reciprocating manneralong a path constrained by a guidance means (160), which is, in theembodiment shown, the interior surface (124) of the housing (120).Movement of electromagnetically active mass (140) relative to thehousing (120) causes motion of said mass-engaged second end of eachspring (130 and 132) with respect to said housing-engaged first end ofeach spring (130 and 132) such that the motion of theelectromagnetically active mass (140) relative to the housing (120)results in deflection of the springs (130 and 132). The device (110)further comprises an induction coil (150) that is engaged about theexterior portion of the housing (120).

As shown in FIG. 2, the device (210) comprises a housing (220) whichcomprises an elongated circular cross-section lube having a first andsecond ends. The housing (220) comprises an internal cavity (222)defined by the lube, an interior surface (224), an atmospheresubstantially similar to the ambient atmosphere (226), and apertures inthe housing which provide communication between the exterior environmentand the interior cavity (222) of housing (220). The device furthercomprises a first spring (230) having a first end and a second end.Spring (230) comprises a compression coil spring having said first endattached to the first end portion of the housing (220). The devicefurther comprises a second spring (232) having a first end and a secondend. Spring (232) comprises a compression coil spring having said firstend attached to the first end portion of the housing (220). The device(210) further comprises an electromagnetically active mass (240) engagedwith each spring (230 and 232). The electromagnetically active mass(240) is moveable within said housing (220). The mass (240) moves in areciprocating manner along a path constrained by a guidance means (260)which is, in the embodiment shown, an elongated rod engaged at citherend with housing (220) and passing through a through-hole (242) in theelectromagnetically active mass (240). Movement of electromagneticallyactive mass (240) relative to the housing (220) causes motion of saidmass-engaged second end of each spring (230 and 232) with respect tosaid housing-engaged first end of each spring (230 and 232) such thatthe motion of the mass (240) relative to the housing (220) results indeflection of the springs (230 and 232). The harvester (210) furthercomprises an induction coil (250) engaged about the exterior surface ofthe housing (220).

FIG. 3 shows wave energy generator 300 including float 302 andelectrical energy generator 304 that is located within the interior 306of the float 302.

FIG. 4A shows wave energy generator 300 tethered to the floor 310 of thebody of water 312 via a suitable tether 314. FIG. 4B shows wave energygenerator 300 tethered to the floor 310 of the body of water 312 via asuitable tether 314 and base 316.

FIG. 5 shows wave energy generator 300 in electrical communication withelectrical energy distribution system 400.

According to the illustrative embodiments shown in FIGS. 3-5, thehousing of the linear electrical energy generator is fixed within thefloat of the wave energy generator. Under these conditions, the housingand induction coil of the linear electric energy generator moves inphase with the float of the wave energy generator. Theelectromagnetically active mass, such as a permanent magnet, moves outof phase with the float and housing and induction coil of the linearelectric energy generator, which causes the mass to move through theinduction coil.

The wave energy generator may be free floating within a body of water.According to other embodiments, the wave energy generator may betethered to the floor of the body of water in which it is placed. Itshould be noted that the wave energy generator may be tethered to thefloor of the body of water into which it is placed by any suitabletethering means, such as, without limitation, rope that is typicallyutilized in a marine environment. Alternatively, the wave energygenerator maybe tethered to a base, which, in turn, is anchored to thefloor of the body of water into which the wave energy generator isplaced. The wave energy generator including the float and the electricalenergy generator may be tethered to the floor of the body of water suchthat the float is floating on the surface of the water, or partiallysubmerged in the water, or fully submerged in the water.

It should be noted that the electrical energy generator may bepositioned within the internal cavity of the bouy or float, or it may bepositioned external, yet still engaged, to the float. According toeither embodiment, the induction coil of the electrical energy generatormay be tethered or otherwise anchored to the bottom of the body ofwater. According to this design, the electromagnetically active mass isfree to move reciprocally in relation to the induction coil.

The electrical energy generator may also be engaged with a personalfloatation device, such as a life jacket, life vest, ring bouy, torpedo,or other similar floatation device. The personal floatation device mayalso incorporate a signaling mechanism that is in electrical connectionwith the electrical energy generator, such as an audibly perceptiblesignal, a visually perceptible signal, or both. The wave energy capturesthe kinetic energy of the motion of waves, converts the wave energy intousable electrical energy to power the signaling mechanism to enable theperson attached to the floatation device to be located in a body ofwater during an emergency.

Depending upon the embodiment and desired operational characteristics,it may be desirable to have one or more of the natural frequencies ofthe device similar to one or more of the operational frequencies of thesource of the excitation kinetic energy; or dissimilar to one or more ofthe expected operational frequencies of the source of the excitationkinetic energy by some predetermined amount. In certain embodiments, onenatural frequency of the device may be predetermined to correspond tothe steady state harmonic motion of the wave motion.

While the wave energy generator has been described in connection withvarious illustrative embodiments, as shown in the Figures, it is to beunderstood that other similar embodiments may be used or modificationsand additions may be made to the described embodiments for performingthe same functions. Therefore, the electrical energy generator shouldnot be limited to any single embodiment, but rather construed in breadthand scope in accordance with the recitation of the appended claims.

1. A wave energy generator comprising: a float and an electrical energy generator engaged with said float, said electrical energy generator comprising: a housing having a longitudinal axis, an interior cavity, an interior cavity surface, and an exterior surface; an electrically conductive material positioned about at least a portion of said exterior surface of said housing and extending along at least a portion of said longitudinal axis; electromagnetically active mass positioned within said housing reciprocally movable along at least a portion of said longitudinal axis; a first spring having first and second ends, wherein one of said ends is engaged with said housing and one of said ends is engaged with said electromagnetically active mass; and a second spring having first and second ends, wherein one of said ends is engaged with said housing and one of said ends is engaged with said electromagnetically active mass.
 2. The wave energy generator of claim 1, wherein said electromagnetically active mass is constrained within said housing to minimize or substantially prevent non-reciprocating motion of said electromagnetically active mass within said housing.
 3. The wave energy generator of claim 2, wherein said housing comprises a cylinder or tube.
 4. The wave energy generator of claim 3, wherein said electrically conductive material comprises an induction coil.
 5. The wave energy generator of claim 1, wherein the entirety of said electromagnetically active mass is adapted to pass through the entirely of said induction coil twice during a single reciprocation period.
 6. The wave energy generator of claim 5, wherein said springs comprise coil springs.
 7. The wave energy generator of claim 6, wherein said coil springs comprise extension springs.
 8. The wave energy generator of claim 6, wherein said coil springs comprise compression springs.
 9. The wave energy generator of claim 7, wherein said electromagnetically active mass comprises at least one permanent magnet.
 10. The wave energy generator of claim 9, wherein said electrical energy generator further comprises a shroud at least partially covering said induction coil, said shroud having a high magnetic permeability.
 11. The wave energy generator of claim 10, wherein said shroud comprises a ferromagnetic material.
 12. The wave energy generator of claim 7, wherein said electrical energy generator further comprises a shroud at least partially covering said induction coil, and wherein: said electromagnetically active mass does not comprise a permanent magnet; and said generator comprises a shroud at least partially covering said induction coil, wherein said shroud comprises a permanent magnet.
 13. The wave energy generator of claim 1, further comprising guidance means to minimize or substantially prevent the non-reciprocating motion of said electromagnetically active mass within said housing.
 14. The wave energy generator of claim 13, wherein said guidance means comprises said interior housing surface or shaft engaged with said housing and said electromagnetically active mass.
 15. The wave energy generator of claim 9, wherein said generator is in electrical connection with an electronic device.
 16. A wave energy generator comprising: a float and an electrical energy generator engaged with said float, said electrical energy generator comprising: a housing having a longitudinal axis; electrically conductive material engaged about at least of portion of an exterior surface of said housing and extending along at least a portion of said longitudinal axis; an electromagnetically active mass positioned within said housing, said mass reciprocally movable along at least a portion of said longitudinal axis; a first spring having first and second ends, wherein one of said ends is engaged with said housing and one of said ends in engaged with said electromagnetically active mass; a second spring having first and second ends, wherein one of said ends is engaged with said housing and one of said ends is engaged with said electromagnetically active mass; and a means to mitigate motion retardation of said electromagnetically active mass within the housing.
 17. The wave energy generator of claim 16, wherein said means to mitigate motion retardation of said electromagnetically active mass within the housing comprises: (i) a sub-atmospheric pressure within said housing; (ii) at least one aperture communicating between the interior of said housing and the external environment, (iii) fluid connections between regions of said housing; or (iv) a combination of two or more of (i), (ii), and (iii).
 18. The wave energy generator of claim 16, wherein said housing comprises a cylinder or tube.
 19. The wave energy generator of claim 16, wherein said electrically conductive material comprises an induction coil.
 20. The wave energy generator of claim 19, wherein the entirety of said mass is adapted to pass through the entirety of said coil twice during a single reciprocation period.
 21. The wave energy generator of claim 20, wherein said springs comprise coil springs.
 22. The wave energy generator of claim 21, wherein said first and second coil springs comprise extension springs.
 23. The wave energy generator of claim 21, wherein said first and second coil springs comprise compression springs.
 24. The wave energy generator of claim 22, wherein said electromagnetically active mass comprises at least one permanent magnet.
 25. The wave energy generator of claim 24, wherein said electrical energy generator further comprises a shroud at least partially covering said induction coil, said shroud having a high magnetic permeability.
 26. The wave energy generator of claim 25, wherein said shroud comprises a ferromagnetic material.
 27. The wave energy generator of claim 24, wherein said electrical energy generator further comprises a shroud at least partially covering said induction coil, and wherein: said electromagnetically active mass does not comprise a permanent magnet; and said generator comprises a shroud at least partially covering said induction coil, wherein said shroud comprises a permanent magnet.
 28. The wave energy generator of claim 16, wherein said means to mitigate motion retardation (i) comprises partial or substantially complete evacuation of said housing.
 29. The wave energy generator of claim 16, wherein said means to mitigate motion retardation (iii) comprises flutes in at least one of the electromagnetically active mass and said housing to prevent isolation of regions of the interior cavity of said housing.
 30. The wave energy generator of claim 16, wherein said electromagnetically active mass is constrained within said housing to minimize or substantially prevent non-reciprocating motion of said electromagnetically active mass within said housing.
 31. The wave energy generator of claim 16, further comprising at least one spring deflection adjuster engaged with said housing and at least one of said springs.
 32. The wave energy generator of claim 31, wherein said spring deflection adjustor comprises: a threaded receiver engaged with said housing; and a threaded member rotatably engaged with said threaded receiver to permit helical motion of said threaded member with respect to said housing.
 33. The wave energy generator of claim 31, wherein said housing comprises a cylinder or tube.
 34. The wave energy generator of claim of 33, wherein said electrically conductive material comprises an induction coil.
 35. The wave energy generator of claim 34, wherein said springs comprise coil springs.
 36. The wave energy generator of claim 35, wherein said coil springs comprise extension springs.
 37. The wave energy generator of claim 35, wherein said coil springs comprise compression springs.
 38. The wave energy generator of claim 36, wherein the entirety of said electromagnetically active mass is adapted to pass through the entirety of said induction coil twice during a single reciprocation period.
 39. The wave energy generator of claim 38, wherein said mass comprises a permanent magnet.
 40. The wave energy generator of claim 39, wherein said generator further comprises a shroud at least partially covering said induction coil, said shroud having a high magnetic permeability.
 41. The wave energy generator of claim 40, wherein said shroud comprises a ferromagnetic material.
 42. The wave energy generator of claim 35 wherein: said electromagnetically active mass does not comprise a permanent magnet; and said generator comprises a shroud at least partially covering said induction coil, wherein said shroud comprises a permanent magnet.
 43. The wave energy generator of claim 32, wherein said threaded members comprise male threaded shafts.
 44. The wave energy generator of claim 32, wherein said threaded receivers comprise female threads integrally formed in said housing. 